Torque indicating wrench

Abstract

A torque applying and indicating wrench is comprised of a pawl with a torque sensing end for both ratcheting, and direct sensing of torque during application. The torque sensing end is bifurcated into a cantilevered flexing beam and an optional reference beam. The flexing beam engages one or more ratchet teeth from a ratchet wheel contained in the wrench head of an elongated tool body. Torque is then transduced and indicated either mechanically or electronically.

I claim: 
     
       1. A torque applying and indicating tool, comprising: a tool body having proximal and distal ends;   a ratchet wheel disposed at said distal end of said tool body;   a pawl nested within said distal end of said tool body and having a torque sensing end and an opposing end, said torque sensing end adapted to movably engage with and be deflected by said ratchet wheel; and   a means for transducing deflection of said sensing end into a means for indicating torque.   
     
     
       2. The tool as recited in claim 1, wherein said torque sensing end of said pawl comprises a cantilevered flexing beam. 
     
     
       3. The tool as recited in claim 2, wherein said transducing means comprises a strain gauge coupled to said flexing beam, and adapted for measuring deflection of said flexing beam and transmitting a signal proportional to said measured deflection to said indicating means. 
     
     
       4. The tool as recited in claim 1, wherein said transducing means comprises: an electronic detecting means, having first and second elements;   said first element disposed at said distal end of said tool body;   said second element disposed on said torque sensing end of said pawl in proximity to said first element; and   wherein said electronic detecting means is adapted to transmit a signal to said indicating means, said signal having a value proportional to the deflection of said torque sensing end.   
     
     
       5. The tool as recited in claim 1, wherein said transducing means comprises: a Hall effect sensor disposed at said distal end of said tool body;   a magnet disposed on said torque sensing end of said pawl in proximity to said Hall effect sensor; and   wherein said Hall effect sensor is adapted to transmit a signal to said indicating means, said signal having a value proportional to the deflection of said torque sensing end.   
     
     
       6. The tool as recited in claim 1, wherein said transducing means comprises: a magnet disposed at said distal end of said tool body;   a Hall effect sensor disposed on said torque sensing end of said pawl in proximity to said magnet; and   wherein said Hall effect sensor is adapted to transmit a signal to said indicating means, said signal having a value proportional to the deflection of said torque sensing end.   
     
     
       7. The tool as recited in claim 1, wherein said transducing means comprises: a capacitive sensor having first and second capacitance plates;   said first capacitance plate disposed at said distal end of said tool body;   said second capacitance plate disposed on said torque sensing end of said pawl; and   wherein said capacitive sensor is adapted to transmit a signal to said indicating means, said signal proportional to the deflection of said torque sensing end.   
     
     
       8. The tool as recited in claim 7, wherein said second capacitance plate is said pawl. 
     
     
       9. The tool as recited in claim 1, wherein said sensing end of said pawl further comprises a reference beam juxtaposed said flexing beam, said flexing beam adapted to be movable relative to said reference beam, said beams having a gap interposed therebetween. 
     
     
       10. The tool as recited in claim 9, wherein said transducing means comprises: a rod positioned adjacent to said pawl, said rod having opposing first and second ends, said first end is tapered and slidably wedged between said gap, said rod movable with respect to said pawl upon deflection of said flexing beam; and   said second end of said rod connected to said indicating means.   
     
     
       11. The tool as recited in claim 10, wherein said indicating means comprises: a pointer having distal and proximal ends;   a pivot head connected to said distal end of said pointer, said pivot head mounted to said opposing end of said pawl, said pivot head coupled to said second end of said rod; and   a spring interposed between said pawl and said pivot head, and adapted for driving the deflection of said pointer.   
     
     
       12. The tool as recited in claim 10, wherein said indicating means comprises: a mirror movably mounted to said opposing end of said pawl, and said mirror coupled to said second end of said rod;   a light emitting means located at said proximal end of said tool body, and adapted to project light onto said mirror; and   a spring interposed between said pawl and said mirror, and adapted to drive the movement of said mirror.   
     
     
       13. The tool as recited in claim 1, further comprising a springable means secured to said tool body for urging said sensing end towards said ratchet wheel. 
     
     
       14. The tool as recited in claim 1, wherein said proximal end of said tool body has a graduated scale located thereon. 
     
     
       15. A torque indicating ratchet wrench, comprising: a tool body having proximal and distal ends;   a ratchet wheel disposed at said distal end of said tool body;   a pawl fitted within said distal end of said body and having a torque sensing end and an opposing end;   said pawl having a fulcrum from which said torque sensing end projects toward said ratchet wheel;   said torque sensing end adapted for movable engagement with and deflected by said ratchet wheel; and   a means for transmitting deflection of said torque sensing end to a means for indicating torque.   
     
     
       16. The ratchet wrench as recited in claim 15, wherein said torque sensing end comprises: a flexing beam; and   a reference beam positioned adjacent said flexing beam, said beams having a gap therebetween.   
     
     
       17. The ratchet wrench as recited in claim 16, wherein said transmitting means comprises: a rod positioned parallel to said pawl and having distal and proximal ends, said distal end tapered and movably disposed between said beams; and   said proximal end of said rod coupled to said indicating means.   
     
     
       18. The ratchet wrench as recited in claim 17, wherein said indicating means comprises: a pivot head mounted to said opposing end of said pawl, said pivot head adapted to interface with said proximal end of said rod;   a pointer connected to said pivot head and projecting toward said proximal end of said tool body; and   a rotational bias means disposed between said pawl and said pivot head, said bias means adapted for driving the rotation of said pivot head.   
     
     
       19. The ratchet wrench as recited in claim 18, wherein said rotational bias means is a spring. 
     
     
       20. A method for applying and indicating torque, comprising: providing a tool body having proximal and distal ends;   disposing a ratchet wheel at the distal end of the tool body;   nesting a pawl within the distal end of the tool body, the pawl having a torque sensing end and an opposing end;   engaging the sensing end of the pawl to the ratchet wheel;   deflecting the sensing end of the pawl upon movement of said ratchet wheel with respect to the tool body; and   transducing the deflection of the sensing end and indicating torque value based thereon.